1. Field of the Invention
The present invention relates in general to a vehicle wheel information obtaining apparatus for obtaining wheel information relating to a vehicle wheel, and more particularly to techniques for registration of an identification data identifying the wheel.
2. Discussion of Related Art
JP-A-2000-233615 discloses a vehicle wheel information obtaining apparatus to be installed on a vehicle, for registering wheel identification information identifying wheels of the vehicle. In this apparatus in which a data communication is established between each local unit provided on a corresponding one of the wheels and a central unit provided on a body of the vehicle, a number of receptions of each identification code by the central unit within a predetermined length of time is counted. It is determined that ones of the identification codes, each of which has been received a relatively large number of times within the predetermined length of time, has been transmitted from the respective wheels of the vehicle in question, rather than from wheels of another vehicle. Thus, the ones of the identification codes received by the central unit with relatively high frequency are registered as the wheel identification data identifying the wheels of the vehicle in question. This arrangement is effective to avoid an erroneous registration in which the identification codes transmitted from the other vehicle are registered as the wheel identification data, even if the other vehicle is positioned close to the vehicle in question.
However, this vehicle wheel information obtaining apparatus disclosed by the Japanese publication suffers from a problem that the apparatus requires a large length of time for completing the registration of the wheel identification information.